People enjoy eating quality food that is prepared by good restaurants. Nevertheless, sometimes people may not want to go to a restaurant, but instead may prefer to have food delivered to them. To meet this demand, a courier may deliver food prepared by a restaurant to a customer at a delivery location. For example, a service may enable customers to order food items from any of a variety of restaurants, and may arrange for couriers to deliver the food items from the restaurants to the customers. However, if it takes too long for the courier to deliver the food from the restaurant to the customer, the food items may be delivered late, may be delivered cold, and/or may be delivered under other unsatisfactory circumstances. Accordingly, a restaurant with a delivery service will usually establish a fixed delivery zone and will not deliver to customers located outside of this fixed zone.